Teacher s dial



(No Model.)

A. M. EDWARDS.

TEAGHER'S DIAL.

No. 407,1 3. Patented July 16, 1889.

Rventov lUi/tnesgses UNITED STATES PATENT OF ICE.

AYRES MASON EDIVARDS, OF LENVISTON, MAINE.

TEACH ERS DIAL.

SPECIFICATION forming part of Letters Patent No. 407,183, dated July 16,1889.

Application filed April 19, 1889. Serial No. 307,809. (No model.)

To all whmn it may concern:

Be it known that I, AYRES MAso EDWARDS, residing at Lewiston, in thecounty of Androscoggin and State of Maine, have invented certain new anduseful Improvements in Teachers Dials; and I do hereby declare that thefollowing is a full, clear, and exact description of the invention,which will enable others skilled in the art to which it appertains tomake and use the same.

My invention relates to a dial fitted up with appliances for teachingnumbers, time, &c., and is designed for the use of teachers.

The device consists of a dial provided with the usual hour and minutehands geared together as in the common clock-movem ent, means beingprovided for disconnecting the two hands with hand-wheels for rotatingboth hands together, as in the regular clock-movement, or theminute-handalone, as desired.

In the accompanying drawings I have illus trated the preferable mannerof constructing my dial.

In the drawings, Figure 1 represents a face view of my dial. Fig. 2represents a back view, and Fig. 3 is a section on the line mm of Fig.

A is a dial, which I prefer to make of heavy paper-board, the usualnumbers or figures being marked or printed on it. The dial A is attachedto a rigid back A, of wood or other suitable material. The usualhour-hand B an d minute-hand G are attached, respectively,

' to the hour-hand dial-wheel H and to the center post F. On the centerpost is the center pinion H.

J is a pintle to which is secured the dialwheel G and the pinion G,which engage, respectively, the center pinion H and the hourhanddial-wheel H, and by which the motion of the minute-hand is imparted tothe hourhand.

E is the casing, to which the gears are pivoted.

The parts thus far described are of the ordinary clock-movementconstruction, and do not, therefore, need further description.

I will now describe the additions and changes which embody my invention.

On the end of the center post F, I secure a gear or pinion H which isadapted to engage a gear (1, acting at right angles to it. The

gear (1* is secured to the end of a shaft 1), which extends parallelwith the face of the dial and somewhat beyond the edge thereof. Theshaft turns in suitable bearings d d, and has secured to its end a knobor handle (1'. The pintle J is so constructed as to have a longitudinalmovement in its bearings. A spring J is secured in a recess in the backA and impinges on the inner end of the pintle, forcing it continuallyoutward. A cam or eccentric (Z acts on the outer end of the pintle J todepress it against the force of the spring J. The cam (Z is secured tothe end of a shaft D, which, as here shown, extends side by side withthe shaft D and is supported in bearings (1 It also has secured to itsend a knob or handle (I. WVhen the cam (l is rotated by turning the knobd, the pintle J is pressed inward, and the dial-wheel G and the pinion Gare made to engage the pinion II and the hour-hand dial-wheel H. If,now, with these gears in engagement the minute hand is rotated, thehour-hand will turn with the ordinary clock-motion. The minute-hand isturned and placed in any desired position by means of the knob (Z.

If it is desired to move the minute-hand independently of the hour-hand,the knob (Z is turned until the cam allows the pintle to be pushed up bythe spring J until the wheels G and G are disengaged. The minute-handcan then be turned by the knob d in either direction without moving thehour-hand. In teaching numbers and time it is often desirable to turnthe minute-hand independently, as shown, and the readiness with which itcan be engaged and disengaged from the hourhand renders the device veryuseful for purposes of instruction.

Although the dial is made primarily for the use of teachers, it may beused to indicate the time of arrival and departure of trains, and forother like purposes.

I claim- 1. The herein-described tcachers dial, having an hour and aminute hand, an hour-hand dial-wheel and a center pinion connected withISO pinion out of gear, and a cam for forcing them into gear,substantially as shown.

2. The herein-described teachers dial, having an hour-hand and anhour-hand dial-wh eel connected therewith, a minute-hand and a centerpost attached thereto, a center pinion and an extra pinion on saidcenter post, a shaft having on one end a knob or handle and on the otherend a gear for engaging said extra pinion, an independent dial-wheel andpinion adapted to connect said hour and minute hands, and means forthrowing the same in and out of gear, substantially as shown.

5 The pintle movable longitudinally in its AYRES lNIASON EDWARDS.

\Vitnesses:

s'ricrnnn A. WUNEL, Nivrimn W. HARRIS.

